NHC-Ir(I) complexes derived from 5,6-dinitrobenzimidazole. Synthesis, characterization and preliminary evaluation of their in vitro anticancer activity

Abstract The design, synthesis, characterization and in vitro anticancer activity of a series of Ir(I) NHC complexes derived from 5,6-dinitrobenzimidazole is reported. The evaluation was performed in five human cancer cell-lines, namely glioblastoma (U-251), prostatic adenocarcinoma (PC-3), colorectal adenocarcinoma (HCT-15), mammary adenocarcinoma (MCF-7) and lung adenocarcinoma (SKLU-7), including healthy cells of African green monkey kidney (COS-7) for comparative purposes. The complexes exhibited better activity in comparison with the corresponding NHC ligand precursors. In particular, complex (4a) exhibited a good performance against PC-3 and SKLU-1 with IC50 values of 10.6 ± 0.9 μM and 10.4 ± 1.5 μM, respectively.